package common;

import org.icepdf.core.pobjects.Document;
import org.icepdf.core.pobjects.Page;
import org.icepdf.core.util.GraphicsRenderingHints;

import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageWriter;
import javax.imageio.stream.ImageOutputStream;
import java.awt.image.BufferedImage;
import java.io.FileOutputStream;
import java.util.Iterator;

public class picture_Example {

    /**
     * 生成一本书的缩略图
     *
     * @param inputFile  需要生成缩略图的书籍的完整路径
     * @param outputFile 生成缩略图的放置路径
     */
    public static void generateBookIamge(String inputFile, String outputFile) {
        Document document = null;

        try {
            float rotation = 0f;
            //缩略图显示倍数，1表示不缩放，0.5表示缩小到50%
            float zoom = 0.8f;

            document = new Document();
            document.setFile(inputFile);
            // maxPages = document.getPageTree().getNumberOfPages();

            BufferedImage p_w_picpath = (BufferedImage) document.getPageImage(0, GraphicsRenderingHints.SCREEN, Page.BOUNDARY_CROPBOX, rotation, zoom);

            Iterator iter = ImageIO.getImageWritersBySuffix("jpg");
            ImageWriter writer = (ImageWriter) iter.next();

            FileOutputStream out = new FileOutputStream(outputFile);
            ImageOutputStream outImage = ImageIO.createImageOutputStream(out);

            writer.setOutput(outImage);
            writer.write(new IIOImage(p_w_picpath, null, null));


        } catch (Exception e) {
            System.out.println("to generate thumbnail of a book fail : " + inputFile);
            System.out.println(e);
        }
    }

    public static void main(String[] args) {
        picture_Example.generateBookIamge("C:\\Users\\hongtang.yang\\Desktop\\f292eabb70ff49ab9fe5a8aa11658114 (1).pdf", "C:\\Users\\hongtang.yang\\Desktop\\11.pdf");
    }

}
